Adjustable trim system for a turbocharger compressor including a ported shroud

Abstract

An adjustable trim system for a turbocharger compressor including a ported shroud for a vehicle propulsion system includes a compressor inlet adjustor positioned in a compressor air inlet and being continuously adjustable between a fully open configuration, a ported shroud closed configuration, and a partially-open ported shroud recirculation configuration between the fully open configuration and the ported shroud closed configuration, and a compressor inlet adjustor control module that adjusts the configuration of the compressor inlet adjustor to a configuration between the fully open configuration and the ported shroud closed configuration when the turbocharger pressure ratio is higher than a predetermined pressure ratio threshold and the compressor corrected air flow into the compressor housing inlet is less than a maximum compressor corrected air flow of a compressor flow map for the turbocharger compressor.

What is claimed is: 
     
       1. A vehicle propulsion system comprising:
 an internal combustion engine having an exhaust system and an intake system; 
 a turbine housing and a turbine wheel mounted in the turbine housing and connected to a rotatable shaft, the turbine housing in communication with the exhaust system for receiving exhaust gas and supplying the exhaust gas to the turbine wheel; 
 a compressor housing and a compressor wheel mounted in the compressor housing and connected to the rotatable shaft, the compressor housing having an air inlet wall defining an air inlet for leading air generally axially into the compressor wheel, the compressor housing further defining a ported shroud system defining a shroud inner wall and a shroud outer wall, wherein the shroud outer wall is spaced radially outward of the shroud inner wall and defining an annular space between the shroud inner wall and the shroud outer wall, a first shroud port formed through the shroud inner wall and extending to the compressor wheel for allowing air to pass between the annular space and the compressor wheel, and a second shroud port formed through the shroud inner wall and extending into the air inlet of the compressor housing and positioned upstream of the first shroud port for allowing air to pass between the annular space and the compressor housing air inlet; 
 a compressor inlet adjustor positioned in the compressor air inlet and being continuously adjustable between a fully open configuration, a ported shroud closed configuration, and a partially-open ported shroud recirculation configuration between the fully open configuration and the ported shroud closed configuration, wherein the compressor air inlet is narrower than the compressor inlet adjustor in the fully open configuration, wherein an inner radius of the compressor inlet adjustor equals an inner radius of the second shroud port in the ported shroud closed configuration such that the second shroud port is closed and the air inlet of the compressor housing is fully open when in the ported shroud closed configuration; 
 a turbocharger compressor temperature module including a compressor inlet air temperature input in communication with a compressor inlet air temperature sensor, and a compressor outlet air temperature input in communication with a compressor outlet air temperature sensor; 
 a turbocharger compressor pressure module including a compressor inlet air pressure input in communication with a compressor inlet air pressure sensor, and a compressor outlet air pressure input in communication with a compressor outlet air pressure sensor, wherein the turbocharger compressor pressure module determines a turbocharger pressure ratio based upon the compressor inlet air pressure input and the compressor outlet air pressure input; 
 a turbocharger compressor corrected air flow module that determines a compressor corrected air flow into the compressor housing air inlet based upon the compressor inlet air temperature input, compressor outlet air temperature input, compressor inlet air pressure input, and compressor outlet air pressure input; and 
 a compressor inlet adjustor control module that adjusts the configuration of the compressor inlet adjustor based upon the turbocharger pressure ratio and the compressor corrected air flow, wherein the compressor inlet adjustor control module adjusts the configuration of the compressor inlet adjustor to a configuration between the fully open configuration and the ported shroud closed configuration when the turbocharger pressure ratio is higher than a predetermined pressure ratio threshold and the compressor corrected air flow into the compressor housing inlet is less than a maximum compressor corrected air flow of a compressor flow map for the turbocharger compressor. 
 
     
     
       2. The system of  claim 1 , wherein the compressor inlet adjustor control module adjusts the configuration of the compressor inlet adjustor to the ported shroud closed configuration when the turbocharger pressure ratio is lower than the predetermined pressure ratio threshold and the compressor corrected air flow into the compressor housing inlet is higher than a predetermined compressor corrected air flow. 
     
     
       3. The system of  claim 1 , wherein the predetermined pressure ratio threshold is between about 2 and 2.8. 
     
     
       4. The system of  claim 3 , wherein the predetermined pressure ratio threshold is about 2.5. 
     
     
       5. The system of  claim 1 , wherein the ported shroud system operates in a recirculation mode whereby air flows from the first shroud port to the second shroud port when the compressor inlet adjustor control module adjusts the configuration of the compressor inlet adjustor to a configuration between the fully open configuration and the ported shroud closed configuration when the turbocharger pressure ratio is higher than the predetermined pressure ratio threshold and the compressor corrected air flow into the compressor housing inlet is less than a maximum compressor corrected air flow of a compressor flow map for the turbocharger compressor. 
     
     
       6. The system of  claim 1 , wherein the compressor inlet adjustor control module adjusts the configuration of the compressor inlet adjustor to a reduced inlet configuration when the turbocharger pressure ratio is lower than the predetermined pressure ratio threshold and the compressor corrected air flow into the compressor housing inlet is less than a predetermined compressor corrected air flow. 
     
     
       7. The system of  claim 6 , wherein an inner radius of the compressor inlet adjustor is less than an inner radius of the second shroud port in the reduced inlet configuration. 
     
     
       8. An adjustable trim system for a turbocharger compressor including a ported shroud for a vehicle propulsion system, the system comprising:
 a turbine housing and a turbine wheel mounted in the turbine housing and connected to a rotatable shaft; 
 a compressor housing and a compressor wheel mounted in the compressor housing and connected to the rotatable shaft, the compressor housing having an air inlet wall defining an air inlet for leading air generally axially into the compressor wheel, the compressor housing further defining a ported shroud system defining a shroud inner wall and a shroud outer wall, wherein the shroud outer wall is spaced radially outward of the shroud inner wall and defining an annular space between the shroud inner wall and the shroud outer wall, a first shroud port formed through the shroud inner wall and extending to the compressor wheel for allowing air to pass between the annular space and the compressor wheel, and a second shroud port formed through the shroud inner wall and extending into the air inlet of the compressor housing and positioned upstream of the first shroud port for allowing air to pass between the annular space and the compressor housing air inlet; 
 a compressor inlet adjustor positioned in the compressor air inlet and being continuously adjustable between a fully open configuration, a ported shroud closed configuration, and a partially-open ported shroud recirculation configuration between the fully open configuration and the ported shroud closed configuration, wherein the compressor air inlet upstream of the compressor inlet adjustor is narrower than the compressor inlet adjustor in the fully open configuration, wherein an inner radius of the compressor inlet adjustor equals an inner radius of the second shroud port in the ported shroud closed configuration such that the second shroud port is closed and the air inlet of the compressor housing is fully open when in the ported shroud closed configuration; 
 a turbocharger compressor temperature module including a compressor inlet air temperature input in communication with a compressor inlet air temperature sensor, and a compressor outlet air temperature input in communication with a compressor outlet air temperature sensor; 
 a turbocharger compressor pressure module including a compressor inlet air pressure input in communication with a compressor inlet air pressure sensor, and a compressor outlet air pressure input in communication with a compressor outlet air pressure sensor, wherein the turbocharger compressor pressure module determines a turbocharger pressure ratio based upon the compressor inlet air pressure input and the compressor outlet air pressure input; 
 a turbocharger compressor corrected air flow module that determines a compressor corrected air flow into the compressor housing air inlet based upon the compressor inlet air temperature input, compressor outlet air temperature input, compressor inlet air pressure input, and compressor outlet air pressure input; and 
 a compressor inlet adjustor control module that adjusts the configuration of the compressor inlet adjustor based upon the turbocharger pressure ratio and the compressor corrected air flow, wherein the compressor inlet adjustor control module adjusts the configuration of the compressor inlet adjustor to a configuration between the fully open configuration and the ported shroud closed configuration when the turbocharger pressure ratio is higher than a predetermined pressure ratio threshold and the compressor corrected air flow into the compressor housing inlet is less than a maximum compressor corrected air flow of a compressor flow map for the turbocharger compressor. 
 
     
     
       9. The system of  claim 8 , wherein the compressor inlet adjustor control module adjusts the configuration of the compressor inlet adjustor to the ported shroud closed configuration when the turbocharger pressure ratio is lower than the predetermined pressure ratio threshold and the compressor corrected air flow into the compressor housing inlet is higher than a predetermined compressor corrected air flow. 
     
     
       10. The system of  claim 8 , wherein the predetermined pressure ratio threshold is between about 2 and 2.8. 
     
     
       11. The system of  claim 10 , wherein the predetermined pressure ratio threshold is about 2.5. 
     
     
       12. The system of  claim 8 , wherein the ported shroud system operates in a recirculation mode whereby air flows from the first shroud port to the second shroud port when the compressor inlet adjustor control module adjusts the configuration of the compressor inlet adjustor to a configuration between the fully open configuration and the ported shroud closed configuration when the turbocharger pressure ratio is higher than the predetermined pressure ratio threshold and the compressor corrected air flow into the compressor housing inlet is less than a maximum compressor corrected air flow of a compressor flow map for the turbocharger compressor. 
     
     
       13. The system of  claim 8 , wherein the compressor inlet adjustor control module adjusts the configuration of the compressor inlet adjustor to a reduced inlet configuration when the turbocharger pressure ratio is lower than the predetermined pressure ratio threshold and the compressor corrected air flow into the compressor housing inlet is less than a predetermined compressor corrected air flow. 
     
     
       14. The system of  claim 13 , wherein an inner radius of the compressor inlet adjustor is less than an inner radius of the second shroud port in the reduced inlet configuration.